Therapeutic effect of interleukin-10 in keloid fibroblasts by suppression of TGF-β/Smad pathway

Inhibition of keloid by 32P isotope radiotherapy through suppressing TGF-β/Smad signaling pathway

BACKGROUND

Keloid seriously affects the appearance, and is accompanied by some symptoms including pain, burning, itching. Radioactive nuclides such as 32P have been proved to be effective in inhibiting the formation of keloid, but the mechanism remains unclear.

METHODS

The keloid animal model was established through keloid tissues implantation. Hematoxylin-Eosin (HE) and Masson staining were performed to investigate histological changes and collagen deposition. The mRNA and protein expression were assessed using RT-PCR and western blotting, respectively. Cell apoptosis and cycle were evaluated through flow cytometry.

RESULTS

Both 32P isotope injection and skin path significantly reduced the size of keloid, and inhibited TGF-β/Smad signaling pathway. SRI-011381, the agonist of TGF-β/Smad signaling pathway, markedly reversed the influence of 32P isotope on cell proliferation, cell apoptosis, cell cycle of LNCaP cells and TGF-β/Smad signaling pathway.

CONCLUSIONS

32P isotope injection and skin path greatly reduced the size of keloid, and the TGF-β/Smad signaling pathway was remarkably inhibited by 32P isotope treatment. The regulation of dermal fibroblast by 32P isotope was reversed by SRI-011381. 32P isotope might inhibit keloid through suppressing TGF-β/Smad signaling pathway. Our study provides a novel therapeutic strategy for the treatment of keloid.

Clinical evaluation of intralesional umbilical cord-derived mesenchymal stem cells, conditioned medium and triamcinolone acetonide injection for keloid treatment: A pilot study

Topical keloid therapy is performed with triamcinolone acetonide (TA) intralesional injection. However, the recurrence rate is high with various side effects. Mesenchymal stem cells (MSCs) have high proliferative abilities and reduce the activity and proliferation of fibroblast cells in keloids. To overcome the costs and limitations, conditioned medium (CM) is used. This study aims to evaluate feasibility of intralesional injection of umbilical cord MSC (UC-MSC) and conditioned medium (UC-CM) compared to TA for keloid therapy. Twenty-four patients with keloids who met the inclusion criteria were included, randomized into three treatment groups and then got assessed for the sociodemographic data, keloid volume, histopathology (type 1:3 collagen ratio), interleukin-10 (IL-10) levels and Patient and Observer Scar Assessment Scale (POSAS) score during visits. Largest volume regression occurred in the UC-MSC group, followed by UC-CM and then the TA group (UC-MSC: 45.32% ± 2.61%; UC-CM: 43.61% ± 3.67%; TA: 28.34% ± 3.81%; p = 0.003). Similar pattern was also observed in increase in IL-10 levels, the decrease in POSAS scores and the reduction of type 1:3 collagen ratio. Hence, UC-MSC and UC-CM are promisingly more effective than TA for keloid therapy, showcasing their superiority in reducing keloid volume, symptoms and type 1:3 collagen ratio, as well as increasing the levels of IL-10.

An updated review of the immunological mechanisms of keloid scars

Keloid is a type of disfiguring pathological scarring unique to human skin. The disorder is characterized by excessive collagen deposition. Immune cell infiltration is a hallmark of both normal and pathological tissue repair. However, the immunopathological mechanisms of keloid remain unclear. Recent studies have uncovered the pivotal role of both innate and adaptive immunity in modulating the aberrant behavior of keloid fibroblasts. Several novel therapeutics attempting to restore regulation of the immune microenvironment have shown variable efficacy. We review the current understanding of keloid immunopathogenesis and highlight the potential roles of immune pathway-specific therapeutics.

Hyperbaric oxygen treatment on keloid tumor immune gene expression

Background:

Hyperbaric oxygen treatment (HBOT) has been demonstrated to influence the keloid recurrence rate after surgery and to relieve keloid symptoms and other pathological processes in keloids. To explore the mechanism of the effect of HBOT on keloids, tumor immune gene expression and immune cell infiltration were studied in this work.

Methods:

From February 2021 to April 2021, HBOT was carried out on keloid patients four times before surgery. Keloid tissue samples were collected and divided into an HBOT group (keloid with HBOT before surgery [HK] group, n = 6) and a non-HBOT group (K group, n = 6). Tumor gene expression was analyzed with an Oncomine Immune Response Research Assay kit. Data were mined with R package. The differentially expressed genes between the groups were compared. Hub genes between the groups were determined and verified with Quantitative Real-time PCR. Immune cell infiltration was analyzed based on CIBERSORT deconvolution algorithm analysis of gene expression and verified with immunohistochemistry (IHC).

Results:

Inflammatory cell infiltration was reduced in the HK group. There were 178 upregulated genes and 217 downregulated genes. Ten hub genes were identified, including Integrin Subunit Alpha M (ITGAM), interleukin (IL)-4, IL-6, IL-2, Protein Tyrosine Phosphatase Receptor Type C (PTPRC), CD86, transforming growth factor (TGF), CD80, CTLA4, and IL-10. CD80, ITGAM, IL-4, and PTPRC with significantly downregulated expression were identified. IL-10 and IL-2 were upregulated in the HK group but without a significant difference. Infiltration differences of CD8 lymphocyte T cells, CD4 lymphocyte T-activated memory cells, and dendritic resting cells were identified with gene CIBERSORT deconvolution algorithm analysis. Infiltration levels of CD4 lymphocyte T cell in the HK group were significantly higher than those of the K group in IHC verification.

Conclusion:

HBOT affected tumor gene expression and immune cell infiltration in keloids. CD4 lymphocyte T cell, especially activated memory CD4⁺T, might be the key regulatory immune cell, and its related gene expression needs further study.

Therapeutic Strategies by Regulating Interleukin Family to Suppress Inflammation in Hypertrophic Scar and Keloid

Hypertrophic scar (HS) and keloid are fibroproliferative disorders (FPDs) of the skin due to aberrant wound healing, which cause disfigured appearance, discomfort, dysfunction, psychological stress, and patient frustration. The unclear pathogenesis behind HS and keloid is partially responsible for the clinical treatment stagnancy. However, there are now increasing evidences suggesting that inflammation is the initiator of HS and keloid formation. Interleukins are known to participate in inflammatory and immune responses, and play a critical role in wound healing and scar formation. In this review, we summarize the function of related interleukins, and focus on their potentials as the therapeutic target for the treatment of HS and keloid.

Adiponectin, but Not TGF-β1, CTGF, IL-6 or TNF-α, May Be a Potential Anti-Inflammation and Anti-Fibrosis Factor in Keloid

INTRODUCTION

Numerous studies have elucidated adiponectin as a negative impact on inflammation and tissue fibrosis. However, little is known about the relevance between adiponectin and inflammatory factors in keloid.

METHODS

To clarify whether adiponectin plays a role in the inflammation and fibrosis of keloid, 50 patients with keloid and 50 healthy subjects were enrolled, We examined the serum and mRNA expression levels of adiponectin, TGF-β1, CTGF, IL-6 and TNF-α in normal skin tissues and keloid tissues by ELISA and qPCR, respectively. Correlation analysis between serum concentration of adiponectin with Vancouver Scar Scale (VSS) scores and the age of patients with keloid was evaluated, and the adiponectin concentrations in patients with keloid between different genders were measured. We further examined the effects of adiponectin on TGF-β1 mediated expression of collagen I, FN and MMP-1 in normal fibroblasts (NFs) and keloid fibroblasts (KFs).

RESULTS

We discovered that lower serum concentration and mRNA expression of adiponectin, but higher TGF-β1, CTGF, IL-6 and TNF-α levels were measured in patients with keloid compared with those in normal controls. Furthermore, there was a strong inverse correlation between the serum adiponectin levels and VSS scores in patients with keloid, but not in ages, and there was no statistically difference between different genders. Moreover, adiponectin attenuated TGF-β1 mediated expression of collagen I and FN, and upregulated the expression level of MMP-1 in KFs, but not in NFs. In addition, the inhibitory effect of adiponectin on TGF-β1 was attenuated by AMPK inhibitor Compound C, but not PI3K/Akt inhibitor LY294002.

DISCUSSION

Adiponectin may exert an anti-inflammation and anti-fibrosis role in the development of keloid. One of the underlying mechanisms may be the activation of the AMPK signaling pathway.

A Plausible Role for Collectins in Skin Immune Homeostasis

The skin is a complex organ that faces the external environment and participates in the innate immune system. Skin immune homeostasis is necessary to defend against external microorganisms and to recover from stress to the skin. This homeostasis depends on interactions among a variety of cells, cytokines, and the complement system. Collectins belong to the lectin pathway of the complement system, and have various roles in innate immune responses. Mannose-binding lectin (MBL), collectin kidney 1, and liver (CL-K1, CL-L1) activate the lectin pathway, while all have multiple functions, including recognition of pathogens, opsonization of phagocytosis, and modulation of cytokine-mediated inflammatory responses. Certain collectins are localized in the skin, and their expressions change during skin diseases. In this review, we summarize important advances in our understanding of how MBL, surfactant proteins A and D, CL-L1, and CL-K1 function in skin immune homeostasis. Based on the potential roles of collectins in skin diseases, we suggest therapeutic strategies for skin diseases through the targeting of collectins and relevant regulators.